mesa: fixes for srgb, new srgb formats

add some more srgb texture formats, including compressed ones
various fixes relating to srgb formats

issues: _mesa_get_teximage is completely broken for srgb textures,
        both for non-compressed ones (swizzling) and compressed ones
        (shouldn't do standard-to-linear conversion)
        texelFetch function may be broken for little or big endian
        (or both...)

1 files changed, 169 insertions, 15 deletions

diff --git a/src/mesa/main/texcompress_s3tc.c b/src/mesa/main/texcompress_s3tc.c
index 4f329cdf59..ccc007c24d 100644
--- a/src/mesa/main/texcompress_s3tc.c
+++ b/src/mesa/main/texcompress_s3tc.c
@@ -3,6 +3,7 @@
  * Version:  6.5.3
  *
  * Copyright (C) 1999-2007  Brian Paul   All Rights Reserved.
+ * Copyright (c) 2008 VMware, Inc.
  *
  * Permission is hereby granted, free of charge, to any person obtaining a
  * copy of this software and associated documentation files (the "Software"),
@@ -56,6 +57,34 @@
 #define DXTN_LIBNAME "libtxc_dxtn.so"
 #endif
 
+#if FEATURE_EXT_texture_sRGB
+/**
+ * Convert an 8-bit sRGB value from non-linear space to a
+ * linear RGB value in [0, 1].
+ * Implemented with a 256-entry lookup table.
+ */
+static INLINE GLfloat
+nonlinear_to_linear(GLubyte cs8)
+{
+   static GLfloat table[256];
+   static GLboolean tableReady = GL_FALSE;
+   if (!tableReady) {
+      /* compute lookup table now */
+      GLuint i;
+      for (i = 0; i < 256; i++) {
+         const GLfloat cs = UBYTE_TO_FLOAT(i);
+         if (cs <= 0.04045) {
+            table[i] = cs / 12.92f;
+         }
+         else {
+            table[i] = (GLfloat) _mesa_pow((cs + 0.055) / 1.055, 2.4);
+         }
+      }
+      tableReady = GL_TRUE;
+   }
+   return table[cs8];
+}
+#endif /* FEATURE_EXT_texture_sRGB */
 
 typedef void (*dxtFetchTexelFuncExt)( GLint srcRowstride, GLubyte *pixdata, GLint col, GLint row, GLvoid *texelOut );
 
@@ -552,6 +581,59 @@ fetch_texel_2d_f_rgba_dxt5( const struct gl_texture_image *texImage,
    texel[ACOMP] = CHAN_TO_FLOAT(rgba[ACOMP]);
 }
 
+#if FEATURE_EXT_texture_sRGB
+static void
+fetch_texel_2d_f_srgb_dxt1( const struct gl_texture_image *texImage,
+                            GLint i, GLint j, GLint k, GLfloat *texel )
+{
+   /* just sample as GLchan and convert to float here */
+   GLchan rgba[4];
+   fetch_texel_2d_rgb_dxt1(texImage, i, j, k, rgba);
+   texel[RCOMP] = nonlinear_to_linear(rgba[RCOMP]);
+   texel[GCOMP] = nonlinear_to_linear(rgba[GCOMP]);
+   texel[BCOMP] = nonlinear_to_linear(rgba[BCOMP]);
+   texel[ACOMP] = CHAN_TO_FLOAT(rgba[ACOMP]);
+}
+
+static void
+fetch_texel_2d_f_srgba_dxt1( const struct gl_texture_image *texImage,
+                             GLint i, GLint j, GLint k, GLfloat *texel )
+{
+   /* just sample as GLchan and convert to float here */
+   GLchan rgba[4];
+   fetch_texel_2d_rgba_dxt1(texImage, i, j, k, rgba);
+   texel[RCOMP] = nonlinear_to_linear(rgba[RCOMP]);
+   texel[GCOMP] = nonlinear_to_linear(rgba[GCOMP]);
+   texel[BCOMP] = nonlinear_to_linear(rgba[BCOMP]);
+   texel[ACOMP] = CHAN_TO_FLOAT(rgba[ACOMP]);
+}
+
+static void
+fetch_texel_2d_f_srgba_dxt3( const struct gl_texture_image *texImage,
+                             GLint i, GLint j, GLint k, GLfloat *texel )
+{
+   /* just sample as GLchan and convert to float here */
+   GLchan rgba[4];
+   fetch_texel_2d_rgba_dxt3(texImage, i, j, k, rgba);
+   texel[RCOMP] = nonlinear_to_linear(rgba[RCOMP]);
+   texel[GCOMP] = nonlinear_to_linear(rgba[GCOMP]);
+   texel[BCOMP] = nonlinear_to_linear(rgba[BCOMP]);
+   texel[ACOMP] = CHAN_TO_FLOAT(rgba[ACOMP]);
+}
+
+static void
+fetch_texel_2d_f_srgba_dxt5( const struct gl_texture_image *texImage,
+                             GLint i, GLint j, GLint k, GLfloat *texel )
+{
+   /* just sample as GLchan and convert to float here */
+   GLchan rgba[4];
+   fetch_texel_2d_rgba_dxt5(texImage, i, j, k, rgba);
+   texel[RCOMP] = nonlinear_to_linear(rgba[RCOMP]);
+   texel[GCOMP] = nonlinear_to_linear(rgba[GCOMP]);
+   texel[BCOMP] = nonlinear_to_linear(rgba[BCOMP]);
+   texel[ACOMP] = CHAN_TO_FLOAT(rgba[ACOMP]);
+}
+#endif
 
 const struct gl_texture_format _mesa_texformat_rgb_dxt1 = {
    MESA_FORMAT_RGB_DXT1,		/* MesaFormat */
@@ -577,6 +659,78 @@ const struct gl_texture_format _mesa_texformat_rgb_dxt1 = {
    NULL					/* StoreTexel */
 };
 
+const struct gl_texture_format _mesa_texformat_rgba_dxt1 = {
+   MESA_FORMAT_RGBA_DXT1,		/* MesaFormat */
+   GL_RGBA,				/* BaseFormat */
+   GL_UNSIGNED_NORMALIZED_ARB,		/* DataType */
+   4, /*approx*/			/* RedBits */
+   4, /*approx*/			/* GreenBits */
+   4, /*approx*/			/* BlueBits */
+   1, /*approx*/			/* AlphaBits */
+   0,					/* LuminanceBits */
+   0,					/* IntensityBits */
+   0,					/* IndexBits */
+   0,					/* DepthBits */
+   0,					/* StencilBits */
+   0,					/* TexelBytes */
+   texstore_rgba_dxt1,			/* StoreTexImageFunc */
+   NULL, /*impossible*/ 		/* FetchTexel1D */
+   fetch_texel_2d_rgba_dxt1, 		/* FetchTexel2D */
+   NULL, /*impossible*/ 		/* FetchTexel3D */
+   NULL, /*impossible*/ 		/* FetchTexel1Df */
+   fetch_texel_2d_f_rgba_dxt1, 		/* FetchTexel2Df */
+   NULL, /*impossible*/ 		/* FetchTexel3Df */
+   NULL					/* StoreTexel */
+};
+
+const struct gl_texture_format _mesa_texformat_rgba_dxt3 = {
+   MESA_FORMAT_RGBA_DXT3,		/* MesaFormat */
+   GL_RGBA,				/* BaseFormat */
+   GL_UNSIGNED_NORMALIZED_ARB,		/* DataType */
+   4, /*approx*/			/* RedBits */
+   4, /*approx*/			/* GreenBits */
+   4, /*approx*/			/* BlueBits */
+   4, /*approx*/			/* AlphaBits */
+   0,					/* LuminanceBits */
+   0,					/* IntensityBits */
+   0,					/* IndexBits */
+   0,					/* DepthBits */
+   0,					/* StencilBits */
+   0,					/* TexelBytes */
+   texstore_rgba_dxt3,			/* StoreTexImageFunc */
+   NULL, /*impossible*/ 		/* FetchTexel1D */
+   fetch_texel_2d_rgba_dxt3, 		/* FetchTexel2D */
+   NULL, /*impossible*/ 		/* FetchTexel3D */
+   NULL, /*impossible*/ 		/* FetchTexel1Df */
+   fetch_texel_2d_f_rgba_dxt3, 		/* FetchTexel2Df */
+   NULL, /*impossible*/ 		/* FetchTexel3Df */
+   NULL					/* StoreTexel */
+};
+
+const struct gl_texture_format _mesa_texformat_rgba_dxt5 = {
+   MESA_FORMAT_RGBA_DXT5,		/* MesaFormat */
+   GL_RGBA,				/* BaseFormat */
+   GL_UNSIGNED_NORMALIZED_ARB,		/* DataType */
+   4,/*approx*/				/* RedBits */
+   4,/*approx*/				/* GreenBits */
+   4,/*approx*/				/* BlueBits */
+   4,/*approx*/				/* AlphaBits */
+   0,					/* LuminanceBits */
+   0,					/* IntensityBits */
+   0,					/* IndexBits */
+   0,					/* DepthBits */
+   0,					/* StencilBits */
+   0,					/* TexelBytes */
+   texstore_rgba_dxt5,			/* StoreTexImageFunc */
+   NULL, /*impossible*/ 		/* FetchTexel1D */
+   fetch_texel_2d_rgba_dxt5, 		/* FetchTexel2D */
+   NULL, /*impossible*/ 		/* FetchTexel3D */
+   NULL, /*impossible*/ 		/* FetchTexel1Df */
+   fetch_texel_2d_f_rgba_dxt5, 		/* FetchTexel2Df */
+   NULL, /*impossible*/ 		/* FetchTexel3Df */
+   NULL					/* StoreTexel */
+};
+
 #if FEATURE_EXT_texture_sRGB
 const struct gl_texture_format _mesa_texformat_srgb_dxt1 = {
    MESA_FORMAT_SRGB_DXT1,		/* MesaFormat */
@@ -594,17 +748,16 @@ const struct gl_texture_format _mesa_texformat_srgb_dxt1 = {
    0,					/* TexelBytes */
    texstore_rgb_dxt1,			/* StoreTexImageFunc */
    NULL, /*impossible*/ 		/* FetchTexel1D */
-   fetch_texel_2d_rgb_dxt1, 		/* FetchTexel2D */
+   NULL, 				/* FetchTexel2D */
    NULL, /*impossible*/ 		/* FetchTexel3D */
    NULL, /*impossible*/ 		/* FetchTexel1Df */
-   fetch_texel_2d_f_rgb_dxt1, 		/* FetchTexel2Df */
+   fetch_texel_2d_f_srgb_dxt1, 		/* FetchTexel2Df */
    NULL, /*impossible*/ 		/* FetchTexel3Df */
    NULL					/* StoreTexel */
 };
-#endif
 
-const struct gl_texture_format _mesa_texformat_rgba_dxt1 = {
-   MESA_FORMAT_RGBA_DXT1,		/* MesaFormat */
+const struct gl_texture_format _mesa_texformat_srgba_dxt1 = {
+   MESA_FORMAT_SRGBA_DXT1,		/* MesaFormat */
    GL_RGBA,				/* BaseFormat */
    GL_UNSIGNED_NORMALIZED_ARB,		/* DataType */
    4, /*approx*/			/* RedBits */
@@ -619,16 +772,16 @@ const struct gl_texture_format _mesa_texformat_rgba_dxt1 = {
    0,					/* TexelBytes */
    texstore_rgba_dxt1,			/* StoreTexImageFunc */
    NULL, /*impossible*/ 		/* FetchTexel1D */
-   fetch_texel_2d_rgba_dxt1, 		/* FetchTexel2D */
+   NULL, 				/* FetchTexel2D */
    NULL, /*impossible*/ 		/* FetchTexel3D */
    NULL, /*impossible*/ 		/* FetchTexel1Df */
-   fetch_texel_2d_f_rgba_dxt1, 		/* FetchTexel2Df */
+   fetch_texel_2d_f_srgba_dxt1, 	/* FetchTexel2Df */
    NULL, /*impossible*/ 		/* FetchTexel3Df */
    NULL					/* StoreTexel */
 };
 
-const struct gl_texture_format _mesa_texformat_rgba_dxt3 = {
-   MESA_FORMAT_RGBA_DXT3,		/* MesaFormat */
+const struct gl_texture_format _mesa_texformat_srgba_dxt3 = {
+   MESA_FORMAT_SRGBA_DXT3,		/* MesaFormat */
    GL_RGBA,				/* BaseFormat */
    GL_UNSIGNED_NORMALIZED_ARB,		/* DataType */
    4, /*approx*/			/* RedBits */
@@ -643,16 +796,16 @@ const struct gl_texture_format _mesa_texformat_rgba_dxt3 = {
    0,					/* TexelBytes */
    texstore_rgba_dxt3,			/* StoreTexImageFunc */
    NULL, /*impossible*/ 		/* FetchTexel1D */
-   fetch_texel_2d_rgba_dxt3, 		/* FetchTexel2D */
+   NULL, 				/* FetchTexel2D */
    NULL, /*impossible*/ 		/* FetchTexel3D */
    NULL, /*impossible*/ 		/* FetchTexel1Df */
-   fetch_texel_2d_f_rgba_dxt3, 		/* FetchTexel2Df */
+   fetch_texel_2d_f_srgba_dxt3, 	/* FetchTexel2Df */
    NULL, /*impossible*/ 		/* FetchTexel3Df */
    NULL					/* StoreTexel */
 };
 
-const struct gl_texture_format _mesa_texformat_rgba_dxt5 = {
-   MESA_FORMAT_RGBA_DXT5,		/* MesaFormat */
+const struct gl_texture_format _mesa_texformat_srgba_dxt5 = {
+   MESA_FORMAT_SRGBA_DXT5,		/* MesaFormat */
    GL_RGBA,				/* BaseFormat */
    GL_UNSIGNED_NORMALIZED_ARB,		/* DataType */
    4,/*approx*/				/* RedBits */
@@ -667,10 +820,11 @@ const struct gl_texture_format _mesa_texformat_rgba_dxt5 = {
    0,					/* TexelBytes */
    texstore_rgba_dxt5,			/* StoreTexImageFunc */
    NULL, /*impossible*/ 		/* FetchTexel1D */
-   fetch_texel_2d_rgba_dxt5, 		/* FetchTexel2D */
+   NULL, 				/* FetchTexel2D */
    NULL, /*impossible*/ 		/* FetchTexel3D */
    NULL, /*impossible*/ 		/* FetchTexel1Df */
-   fetch_texel_2d_f_rgba_dxt5, 		/* FetchTexel2Df */
+   fetch_texel_2d_f_srgba_dxt5, 	/* FetchTexel2Df */
    NULL, /*impossible*/ 		/* FetchTexel3Df */
    NULL					/* StoreTexel */
 };
+#endif